The protein composition of hereditary cataractous lens will be investigated by fractionation procedure with anion exchange cellulose. The separated crystallin groups will be characterized by composition analysis, SDS-gel electrophoresis and isoelectric focusing in gels, as well as -SH and protein-bound glutathione levels. The high molecular proteins of cataractous human lenses will be characterized for the size and molecular weight distribution employing sedimentation analysis and electron microscopy. The cross-linked region of high m.w. proteins will be labled by NaBT4 and subjected to chemical and enzymatic cleavage with NaIO4, CNBr and proteolytic enzymes. The cross-linked peptides will be separated and analyzed for the possible presence of Schiff base type compounds by chromatography. The glutathione, glutathione reductase, glutathione peroxidase and Na-K ions activated membrane-bound ATPase levels of hereditary cataractous lenses will be determined at different stages of development of cataract. Furthermore, the relationship between cataract formation in senile normal rats and the ATPase activity will be investigated. The effect of antioxidants (e.g. butylated hydroxytoluene) feeding on the course of development of cataract in hereditary cataractous and senile rats will be investigated and correlated to the levels of glutathione and membrane-bound ATPase activity.